discreetly

Acting in a discreet manner; acting in a way that respects privacy or secrecy; quietly

Mao was animated and following every nuance of the conversation, but I could see that he was also becoming very tired. Chou had been discreetly glancing at his watch with increasing frequency, so I decided that I should try to bring the session to a close.

inconspicuously

And, placed discreetly among these commonplaces, a few pieces of genuine quality, bizarrely distinguished by craftsmanship from the vulgar products of the machine.

A Forest Trail and wild life hides lie 2 miles to the north-east. Blue hares, deer, wild geese, herons and duck can be discreetly observed from the hides.